Cool AR-15 Cleaning Tools – Cat M4 & Brownells Radius Bolt Scraper

It could be a fun weekend shooting with friends, a 3-gun competition, civil disturbance, or zombie apocalypse (I know, so overdone). Guns get dirty, carbon builds up in all the typical places and guns lose accuracy and reliability. A quick in-the-field cleaning can keep guns running smoothly and accurately so you don’t find yourself without an operational gun when things are at their worse or best depending on how you look at it.

I’ve seen many articles on AR’s, but few on cleaning. Over the last few years, there have been numerous tools introduced to facilitate easier cleaning of the bolts and carrier groups and I wanted to compare them side by side to see if they worked and if they worked, how well? I called Brownells (who else) and promptly received a package which included:

Cat M-4 Cleaning Tool

The Otis B.O.N.E. (Bolt Operational Necessary Equipment)

CRT-15 Carbon Removal Tool for AR-15

Brownells AR-15 Bolt Radius Scraper

Mark Brown Custom AR-15 Bolt Carrier Carbon Scraper

These items along with 20 boxes of Wolf .223 steel case, military classic ammo which felt dirty, so it was perfect for my project, a few boxes of hand loads from a friend (thanks Ted), and various leftovers from previous range sessions in both 5.56 and .223, I was ready to go.

Getting Dirty

For the evaluations, I needed to shoot. I used my Spikes Tactical 10.5” SBR with a Nickel-Boron bolt group plus a second bolt and carrier, borrowed from my 10” Spikes 300 Blackout, also Nickel-Boron. I then walked 100-yards to the backyard rifle and pistol range – I know, it’s a rough life. Within 10 minutes I was sent away for scaring the crap (literally) out of the wife’s new foster dog. Darnit

A half an hour later I arrived at the public range and started over. I shot 100 rounds then swapped bolts and carriers and as an added bonus, I twisted on an Advanced Armament 7.62 SD suppressor to increase the gas and pressure to the carrier, hopefully making it a bit more carbon coated (remind me to use this when shooting in the backyard). The nickel boron bolt groups performed well and I had no failures from the Spikes rifle. It digested all the various types of ammo with only a few failures-to-feed from the Wolf ammo but surprisingly the accuracy was really good.

The Clean Up

Cat M-4 Cleaning Tool

Pro – Small, simple one piece design, no moving parts. Bonus screw driver tip holder. Good performance and lightweight. It could be worn by women to attract the right type of guy.Con – Not perfect. The Cat M-4 didn’t get all the carbon from the back of the carrier.

Otis B.O.N.E.

Pros – Also small, compact, fits easily into the little OTIS cleaning kits. It did a reasonable job on the bolt and a great job on the carrier. Just as with the CAT, it could be worn by a woman as a pendant to attract the right type of man.Cons – The bone bolt cleaning end felt a bit loose to me.

CRT-15 Carbon Removal Tool for AR-15

Pro – Was the best at getting the carbon off the bolt. It was odd at first applying pressure to the small arm, but easy enough.Con – Small arm may break off and the carrier recess did not get it as clean as the others.

Brownells AR-15 Radius Bolt Scraper

Pro – Did a great job on the bolt tail, removing most of the carbon the first time.Con – This is a larger tool and better suited for the workshop. Only one function.

Mark Brown custom AR-15 Bolt Carrier carbon scraper

Pro – This did a great job cleaning the carrier recess.Cons – This is also a large tool and best suited for the workshop. Only one function.

Conclusion: Size matters. All the tools did a good job knocking the excess carbon from the bolts and carriers. Used in the field I have no doubts that all of them would keep your AR’s running strong. Special thanks to Brownells for an outragous amount of support for this article.

About the authorRick Ross is a NRA Life member, GSSF and IDPA competitor and AR enthusiast. He is not a Rapper.

Editors note: Rick Ross is an independent reviewer and contributor for American Shooting Journal and at times, a known goof ball.